Molten-Salt Reactor Experiment

Molten-Salt Reactor Experiment

The Molten-Salt Reactor Experiment (MSRE) was an experimental nuclear reactor which was operated from 1965 to 1969 by the Oak Ridge National Laboratory (ORNL) in the United States. The MSRE was a 7.4 MWth test reactor simulating the neutronic "kernel" of a type of inherently safer epithermal thorium molten salt breeder reactor.

Design and Operation

The MSRE was a thermal reactor that used a molten salt mixture of lithium, beryllium, and zirconium fluorides as both its reactor coolant and nuclear fuel. The fuel was a mixture of uranium-233 and uranium-235, both of which are fissile materials. The reactor was moderated by graphite.

The MSRE was unique in that it had a liquid fuel, rather than solid fuel rods. This allowed for a much higher operating temperature and a much lower pressure than in a typical pressurized water reactor (PWR), which improved the efficiency of the power cycle.

Results and Legacy

The MSRE was successful in demonstrating the feasibility of molten salt reactors (MSRs) and in developing the technology needed for their operation. The experiment ended in 1969, but the data and experience gained continue to be used in studies of potential new MSRs.

The MSRE was also significant in that it was the first reactor to use uranium-233 as a fuel, a product of thorium irradiation. This demonstrated the feasibility of the thorium fuel cycle, which is seen as a potential way to produce nuclear power with less production of long-lived nuclear waste.

See also

• Liquid fluoride thorium reactor
• Generation IV reactor
• Nuclear power in the United States